flang in llvm.org source tree

Is there a schedule for when flang will be merged into the official llvm.org svn/git source trees instead of having to do standalone custom builds with additional patches?

Seems like this should also go to flang-dev so I'm adding it.

"flang" is basically a legacy project. "f18" is the new ground-up build
of a Fortran LLVM project. f18 is the thing that has the most
likelihood of becoming an "official" LLVM project.

However, it's probably going to be a while before we get there. For one
thing, I haven't seen any posts on flang-dev that talk about making
changes to f18, proposing designs, etc. The development seems
completely opaque right now, which is unfortunate.

I would like to see f18 become "official" sooner rather than later, both
to open up development and to get better code sharing across projects.


Jack Howarth via llvm-dev <llvm-dev@lists.llvm.org> writes:

Now I’m really confused as the ‘flang’ compiler here has lots of recent commits from the Portland Group…


Yes, the projects are proceeding in parallel. As far as I understand
things, development of "flang" will stop when "f18" reaches feature
parity. You would have to ask the NVIDIA people for more information.
I'm just going on information presented at the Webinar a couple of
months back.


Jack Howarth via llvm-dev <llvm-dev@lists.llvm.org> writes:

Does anyone know for sure whether f18 will require the clang front end? My largest complaint about the current flang design is that it requires a patch to the clang to be able to work, which significantly increases repackaging costs. In my personal flang tree, I wrote a new front end so that my version of flang could be built with the stock clang and LLVM, which allows me to upgrade clang and recompile whenever a new LLVM version comes out. I would greatly encourage the NVIDIA developers to do the same for f18.

I also noticed that when attempting to compile f18, even the latest version of clang-cl had trouble handling some of the methods that contained heavy used of std::visit, while Microsoft’s compiler experienced certain internal compiler errors. I hope that these issues will be resolved by the time that flang development is stopped.